New or old hcg?

Brittni

So on 8/29 my hcg level was 75. On 8/31 it was 47. A week later 15. My d&c; was a month and a half ago. And I becasically miscarried 2 months ago. Shouldn't I have gone to 0 already. How does it drop from 75-47 in 2 days and then a week later it's still at 15. I want to be pregnant so I hope it's the very beginning of a new one based off this chart. What do you ladies think?